Oil booms are seen offshore as Brown pelicans nest on Breton Island off the coast of Louisiana in the Gulf of Mexico. Wildlife in the
Breton National Wildlife Refuge, created by Theodore Roosevelt, are vulnerable to the oil spill resulting from the explosion and sinking of the Deepwater Horizon oil rig last week. See the
National Audubon Society's website for further informationPhotograph: Gerald Herbert/AP

A Turkey vulture, undergoing training to detect human remains, is presented at Walsrode's Bird Park. The vulture, usually able to detect decaying flesh at an altitude of 1,000 metres, will be used to find the bodies of missing persons in wooded areas or on difficult terrainPhotograph: John Macdougall/AFP/Getty Images

An adult bald eagle, wearing red tracking tags put in place by biologists, returns to its nest. An unprecedented
study of bald eagle diet will provide wildlife managers with the information necessary to reintroduce bald eagles to the channel islands off California. The scientists, including researchers from the Carnegie Institution's Geophysical Laboratory, found that eagles fed mainly on sea birds from about 20,000 to 30,000 years ago until the 1840s and 50s, when humans introduced sheep. These sea birds provided an abundant source of meat for the local eagle population, until widespread use of the pesticide DDT wiped out the predators in the 1960sPhotograph: Peter Sharpe/Institute for Wildlife Studies

A reclusive Saimaa ringed seal pup in Savonlinna, eastern Finland. There are only around 260 Saimaa ringed seals (
Phoca hispida saimensis) in the lakes of south-eastern Finland. The European Union's executive has said that the country must take urgent steps to protect its population of rare freshwater seals before they are wiped out. The EU's law on nature protection, the habitats directive, lists the Saimaa seal as a priority for protection - imposing strict limits on activities that might endanger the animals, such as net-fishingPhotograph: Timo Sepp L Inen/EPA

A heron inspects an alligator in the fragile wetlands next to the Mississippi river near Venice in Louisiana, which is in the path of oil spreading from the BP Deepwater Horizon platform disasterPhotograph: Mark Ralston/AFP/Getty Images

A wild Przewalski mare (
Equus przewalskii) and her foal are seen next to another horse (right) in the Hortobagy National Park, some 200 kms east of Budapest. The Przewalski or Asian wild horse is an ancient and nearly extinct species originating in Mongolia. It was rediscovered by Russian army officer and explorer Nikolai Przewalski in Mongolia at the end of the 19th century. In 1997, the Hortobagy National Park joined the European Endangered Species Breeding Programme (EEP) of the Federation of European Zoos and 21 przewalski horses were settled there. These days, 137 specimens live in the natural reserve of Hortobagy, with the birth of 30-35 foals expected this May Photograph: Tibor Olah/EPA

A rare Lady's Slipper orchid at Silverdale golf course in Carnforth, Lancashire – the last remaining flowering plant of its kind in the wild in Britain. The flower is so rare that it will receive police protection from thieves when it blooms later this month Photograph: Lancashire Police/PA

Flying fish, like this one swimming at night 30 miles from the Deepwater Horizon explosion, are among many forms of marine life at risk form the ongoing crude oil leakPhotograph: Christopher Berkey/EPA

A may beetle flies near Darmstadt, Germany. Before their life cycle comes to an end in four to six weeks' time, billions of may beetles will exit the soil and devour the leaves of the surrounding trees. Massive numbers of may beetles appear once every four years Photograph: Boris Roessler/EPA

An egret looks for food in the reserve of San Vicente village, Olango island, in the Philippines' Cebu province. Sightings of the yellow-beaked, green-legged bird are becoming less frequent, according to
BirdLife InternationalPhotograph: Ted Aljibe/AFP/Getty Images

A photo of a rare Scottish wildcat taken on the remote island of Mull. Experts are speculating that the animal somehow swam to its new home from the mainland. There have been unconfirmed sightings on the island before but these photos, taken by holidaymaker Peter Harris, give the clearest pictures yetPhotograph: Peter Harris/PA

Mexican biologist Abelardo Brito tries to catch a lionfish near a coral reef along the Cozumel coast in Mexico. The tropical native fish of the Indian and Pacific oceans have colonised large swaths of the eastern seaboard, the Caribbean and recently the Gulf of Mexico, and threatens to wreak ecological chaos as far away as South AmericaPhotograph: Miguel Tovar/AP